Dead Man's Kit(1980)

After shore-leave in Lisbon for the crew of HMS Diana, Master-at-Arms 'Toby' Toberman makes an official complaint to the ship's Captain about the behaviour of an officer he saw in a casino. Following the ship's 'Sod's Opera' party, Toby is reported missing from the deck - presumed lost overboard. Was it an accident or suicide - or was he given the proverbial push?